The present invention relates to a pneumatic tire, more particularly to a tread structure for a summer tire capable of improving steering stability on dry roads and grip performance when used on icy or snow-packed roads.
In the situation that it is necessary to drive a FF car provided with summer tires on icy or snowy roads, it is often the case that tire chains are attached to only the front wheels, namely driven wheels. On the rear wheels, therefore, it is difficult to obtain necessary lateral grip, and the car is liable to skid or fishtail.
It is known in the tire art to use a relatively soft rubber compound as the tread rubber contacting with the ground in order to increase the grip performance of a snow tire during running on icy or snow-packed roads.
However, if such soft tread rubber compound is used in a summer tire, slumping deformation of tread blocks increases due to the lower rigidity of the tread rubber, and the steering stability during running on dry roads is greatly deteriorated.